Protection of submerged piling



May 30, 1967 o. E LIDDELL PROTECTION OF SUBMERGED FILING 2 Sheets-Sheet 1 Filed June 29, 1964 INVENTOR.

021 41 7 5/0054; BY I ATfOP/VEYS i-i. 4 FIGS r16 y 30, 1937 o. E. LIDDELL 3,321,924

PROTECTION OF SUBMERGED FILING Filed June 29, 1964 2 Sheets-Sheet 2 INVENTOR. 021/41 5. L/DDELL ATTOZ/VEK? Patented May 30, 1967 3,321,924 PROTEETIGN F SUBMERGED FILING Orval E. Liddell, R0. Box 1533, Avalon, Calif. 90764 Filed June 29, 1964, Ser. No. 378,852 3 Claims. (Cl. 61-54) The present invention relates to a novel method and apparatus for protecting submerged pilings against damage.

It is a major object of the present invention to provide an improved method and apparatus for protecting a sub merged wooden pile against marine borer attack.

Another object of the present invention is to provide a. method and apparatus for protecting a submerged pile which may be utilized within a limited working space as between the deck of a pier and the water line whereby installation can be accomplished without removel of the decking.

A further object of the present invention is to provide a method and apparatus for protecting a submerged pile capable of use on all lengths and diameter of piles and especially on older but still usable piles such as have had large surface areas eaten away by marine borers so that they no longer have a uniform taper or diameter.

It is also an object of the present invention to provide a protective encasement for submerged piles that may be fabricated from commercially available materials at a cost lower than that of prior devices of this nature where by the expense of protecting new and old piles is greatly reduced.

A more particular object of the present invention is to provide apparatus for protecting a submerged pile which includes a sheet of synthetic plastic material having an inherent ability to return to its relaxed condition after it has been flexed to an expanded position so as to be applied to a submerged pile.

Yet a further object of the present invention is to provide a method for protecting a submerged piling which includes forming a sheet of synthetic plastic material into a convoluted roll having a diameter less than the diameter of said piling, the synthetic plastic material having an inherent ability to return to its relaxed condition. This roll is expanded about the. pile to be protected, with the roll thereafter contracting into close engagement with the piling.

It is a further object of the present invention to provide apparatus for protecting a submerged wooden pile which will aiford protection for such pile over an eX- tended period of time.

Another object of the present invention is to provide an improved method and apparatus for protecting a sub merged metal pile again corrosion attack.

An important object of the present invention is to pro vide an improved method and apparatus for protecting a submerged wooden pile against marine borer attack by creating a generally circumferentially water-filled space between a submerged pile and a convoluted roll of synthetic plastic material to thereby restrict circulation between said space and the water surrounding the sheet. In this manner the water in this space is maintained stagnant and marine borers are prevented from sustaining themselves within said space.

Various other objects and advantages of the present invention will become apparent from the following de tailed description thereof, when taken in conjunction with the annexed drawings wherein:

FIGURE 1 is a side elevational view showing a submerged wooden pile Which is adapted to be protectively encased by means of the method and apparatus embodying the present invention;

FIGURE 2 is a side elevational view showing a sheet 70 of synthetic plastic material utilized in carrying out the present invention;

FIGURE 3 is a perspective view of the synthetic plastic sheet of FIGURE 2 after such sheet has been convoluted into a roll having a diameter less than the diameter of the pile shown in FIGURE 1;

FIGURE 4 is a perspective view showing the convoluted roll of FIGURE 3 being applied to the submerged pile of FIGURE 1;

FIGURE 5 is a, perspective view showing said roll after it has been applied to said pile;

FIGURE6 is a side elevational view showing said roll after it has been secured about said pile;

FIGURE 7 is a side elevational view showing how the convoluted synthetic plastic roll of FIGURE 3 may be applied to the area below and above the mud line surrounding a submerged pile;

FIGURES 8 and 8a are fragmentary perspective views showing a means for reinforcing the side edges of said convoluted roll;

FIGURE 9 is a side elevational view showing a second form of apparatus embodying the present invention being applied to a submerged pile;

FIGURE 10 is an enlarged horizontal sectional view taken on line lit-ll] of FIGURE 9;

FIGURE 11 is a horizontal sectional view taken on the same line as FIGURE 10 showing the apparatus of FIGURE 9 as finally installed on said submerged pile;

FIGURE 12 is a fragmentary vertical sectional view taken on line 12 12 of FIGURE 11;

FIGURE 13 is a fragmentary horizontal sectional view showing a labrynth type of seal for the side edges of said convoluted roll; and

FIGURES 14 through 18 are perspective views showing various types of bands which may be utilized to secure the convoluted roll onto a submerged pile.

In the drawings, the novel method and apparatus embodying the present invention is shown as being particularly adapted for application to submerged wooden piles. It will be apparent to those skilled in the art, however, that the principles herein disclosed are not necessarily so limited and can be utilized with other types of submerged wooden and metal structures.

In general, the preferred form of apparatus embodying the present invention includes a sheet of synthetic plastic material having an inherent memory, that is, a plastic material which will automatically return to its relaxed position after it has been temporarily flexed out of such relaxed position. Suitable synthetic plastic materials which may be compounded to provide this characteristic are polyvinyl chloride, nylon, polyethylene and polyurethane. Such materials should also be compounded into a generally rigid condition. Most of such materials are thermoplastic. Various thermosetting plastics may also be employed, as for example phcnolics reinforced with glass fibers. The details of such compounding are well-known to those skilled in the synthetic plastic art.

Referring now to the drawings, there is shown in FIG- URE 1 a submerged wooden pile P. The portion of this pile P adjacent the water line 2! has been eaten away by marine borers so as to define a cavity 22. It should be understood that the pile P, although reduced from its original strength because of marine borer damage, still has load bearing capacity. A dock or other structure may be assumed as being supported by the upper portion of the pile P.

Referring to FIGURE 2, there is shown a rectangular sheet 24 of a suitable synthetic plastic material as aforesaid. In accordance with the present invention, the sheet 24 is formed into a convoluted roll R that in its normal, relaxed condition has a diameter less than the diameter of the pile P to be protected. Such convoluted roll R is shown in FIGURE 3. In practice, a suitable synthetic plastic material from which the convoluted roll R may be 3 formed is rigid polyvinyl chloride varying in thickness from .030 inch to .090 inch. Once this polyvinyl chloride material is heat-formed into a convoluted roll it has a very high flexural strength as compared to its tensile strength at temperatures below 100 F. A convoluted roll of this material therefore has great resistance to any permanent deformation from its relaxed shape. Such material is said to have an inherent memory. A flat sheet of polyvinyl chloride may be rolled into a small coil at a temperature above the heat distortion temperature of such material, usually from 150 to 200 F. When this convoluted roll of polyvinyl chloride has cooled to ambient temperature it will tend to remain in its convoluted form.

Referring now to FIGURES 4, 5 and 6, there is disclosed a method for installing the convoluted roll R around a submerged piling P. Referring first to FIGURE 4, in order to install the convoluted roll R about the submerged piling P, the roll is flexed open and then expanded around the pile P. As indicated in this figure, this operation may conveniently be conducted by a diver 2e.

Referring now to FIGURE 5, after the convoluted roll R has been expanded around the pile P it is released whereupon it will contract towards its original convoluted position. Since the diameter of the convoluted roll R in its original condition was smaller than the diameter of the submerged pile P, the roll will tightly grip the exterior surfaces of the pile P. This will be true even though the pile P is tapered, the side edges of the convoluted roll R overlapping so as to permit adjustment to the pile taper.

Referring to FIGURE 6, the final step in installing the convoluted roll R about the pile P is to secure the roll to the pile P as by means of a plurality of vertically spaced bands, generally designated 28. It should be understood that although only a single convoluted roll R is disclosed in FIGURES 4, 5 and 6, additional convoluted rolls may 7 be applied to the pile P in a modular fashion so as to cover an extensive pile area.

In FIGURE 7 there is shown a method of installing the convoluted sheet R below the mud line 30 of the body of water suruounding the pile P. To effect such installation, a small crater 32 one or two feet in depth is formed in the mud surrounding the pile P. The crater may be formed by means of a lance 34 that conducts compressed air or Water under pressure from the surface so as to form the crater 32. The convoluted roll R may be applied about the pile P either after or during the forming of the crater 32, but preferably during the forming of the crater. The material of the convoluted roll R should be sufficiently rigid as to permit its lower edge to be forced down through the sand or gravel within the crater 32.

Referring now to FIGURE 8, under certain conditions it is desirable to reinforce one or both of the side edges of the convoluted roll R. In FIGURE 8 such reinforcing takes the form of a generally rigid rod 36 that may be formed of a suitable material such as a rigid synthetic plastic. This rod 36 is held in place by overlapping the side edge 38 of the sheet 24 and thereafter securing such rolled-over edge to the main body of the sheet.

In FIGURE 8a the side edge 40 of the sheet 24 is reinforced by simply forming such edge thicker than the main body of the sheet, as shown at 38'.

Referring now to FIGURES 9 through 12, there is shown a second form of apparatus embodying the present invention. The apparatus shown in these figures includes a vertically extending back-up strip, such as a board 44 which vertically bridges the crater 22 in submerged pile P. The use of the back-up strip 44 is particularly desirable where the cavity 22 is of an extensive nature. As indicated in FIGURE 11, the back-up strip 44 provides a solid support for the overlapped side vertical edges of the convoluted roll R. These edges may be aifixed to the back-up strip 44 as by vertically spaced nails 45. It will be apparent that if the back-up strip 44 were not provided considerable difficulty would be encountered in effecting a secure seal between the overlapped side vertical edges of the roll R.

The apparatus of FIGURES 9 through 12 also includes a pair of horizontal sealing bands 46 and 48 arranged adjacent the upper and lower edges, respectively, of the roll R. Such sealing bands 46 and 48 may be provided of a suitable resilient material such as a polyurethane foam impregnated with asphalt. A similar vertical seal 50 formed of the same material may also be interposed between the overlapped side vertical edges of the roll R. It should be understood that the seal be tween the upper and lower edges of the convoluted roll R and the vertical side edges of such roll should be adequate to restrict circulation between the generally circum erential space enclosed within the convoluted roll and the ambient water surrounding the submerged pile P. In this manner, the water in this space is maintained stagnant and marine borers are prevented from sustaining themselves within this space. The reinforced side vertical edges of FIGURE; 8 and 8a and/ or the back-up strip 44 serve to reinforce the vertical side edges of the convoluted roll R so as to permit the necessary sealing off of the ambient Water from the interior of the convoluted roll even where crater Z2 is extensive. Conveniently, the upper and lower portions of roll R may be formed with protrusions 51 that receive bands 46 and 43.

Another form of suitable vertical sealing means is shown in FIG. 13. The seal of FIGURE 13 is of the labrynth type utilizing a separate vertical strip 51 which is rigidly ailixed alongside the side edge 52 of one of the Side vertical edges of the roll R. The space between the side edge 52; and the strip 511 defines a groove 53 that ealingly receives the opposite side vertical edge of the roll R. The type of seal shown in FIGURE 13 affords excellent results particularly where turbulent water conditions are encountered, as from the wash from ships screws.

Referring now to FIGURES 14 through 18, there are shown various forms of bands which may be utilized to secure the convoluted roll R to the submerged pile P. The band member '60 shown in FIGURE 13 includes a resilient steel strip which is preformed to the spiral configuration indicated in this figure. This steel strip is covered with a waterproof material such as a natural or synthetic rubber or a synthetic plastic. The relaxed diameter of the band 60 is less than that of the pile P. The band (it) is easily applied over a pile-mounted convoluted roll R by simply flexing the sides of the band apart and thereafter permitting the band to snap back into its relaxed position of FIGURE 14.

In FIGURE 15 there is shown a very simple band 62 comprising a corrosion resistant wire that is wrapped about the pile-mounted convoluted roll R and'its ends thereafter being twisted together. Conveniently, the wire may be covered with a coating of polyvinyl chloride so as to be rendered corrosion resistant.

In FIGURES l6 and 17 there is shown a band 64 utilizing metal or synthetic plastic strapping 66 having its opposite ends secured by means of a clamp 68.

Referring to FIGURE 18, the band member 70 shown therein is formed of any suitable elastic material, such as natural or synthetic rubber or synthetic plastic. The band member 7d has a length approximately the same as the circumference of the portion of the submerged pile P whcreon it is to be applied. At one of its ends the band member is formed with a longitudinally elongated eye 72 adapted for cooperative engagement by a hook 74 formed in the opposite end of the band member. Inasmuch as the band member is preferably in a state of tension when wrapped about the convoluted rol-l R, the eye 72 and hook '74 should be of such configuration as to avoid the rupture of the material of the band particularly at the eye. This is important for insuring a long service life for the band member.

It is important to observe that the apparatus of the present invention may be installed on a submerged pile with-out disturbing the structure supported by the pile. Additionally, the convoluted rolls are readily removable with respect to a submerged pile. This permits periodic inspections of the portion of the pile below the convoluted roll. Additionally, this feature permits vertical adjustment of the convoluted roll to change its position to meet a change in the area of the pile subjected to marine borer attack. For example, if the mud line 32 shown in FIGURE 7 should lower, as it will in some locations, to such an extent that it exposes the lower end of the pile below the convoluted roll R, the roll can be easily lowered into a new position in a new crater and once again secured in place.

In the use of the apparatus of the present invention the convoluted rolls can be applied to new pilings in lieu of the conventional creosote or any other protection. Alternatively, a newly creosoted pile may be put in place and left without the protection of the convoluted ro-lls until such time as a substantial part of the creosote has been leached from the pile. These encasements are then applied to the pile to arrest any marine borer activity which has already ensued and to prevent any further marine borer attack. This greatly extends the service life of an initially creosoted pile.

The apparatus of the present invention is useful in protecting submerged piling, both wood and metal, from abrasion, and also for protecting metal piling from corrosion.

Various modifications and changes may be made with respect to the foregoing detailed description, as for example, the roll R shown in FIGURE 5 could be secured in place by means of a suitable adhesive deposited along the overlapped vertical edges of the roll. Such modifications and changes, however, do not depart from the spirit of the invention nor the scope of the following claims.

I claim:

1. A method of protectively encasing a partially su'bmerged pile in situ, comprising:

forming a sheet of synthetic plastic material into a convoluted roll having a diameter less than the diameter of said piling, said material having an inherent memory;

expanding said roll about said pile, said roll thereafter contracting into close engagement with said pile because of said inherent memory;

securing said roll to said pile;

and sealing the space between said pile and said roll from the ambient water surrounding said pile sufficiently to maintain the water in said space stagnant to prevent marine borer attack on said pile.

2. A method of protectively encasing a partially submerged pile in situ, comprising:

forming a sheet of synthetic plastic material into a convoluted roll having a diameter less than the diameter of said piling, said material having an inherent memory;

expanding said roll about said pile, said r011 thereafter contracting into close engagement with said pile because of said inherent memory;

securing said roll to said pile with the vertical edges of said roll overlapped;

stiffening said overlapped side edges;

and sealing the space between said pile and said roll from the ambient water surrounding said pile sufficiently to maintain the water in said space stagnant to prevent marine borer attack on said pile.

3. A method of protectively encasing a partially submerged pile in situ, comprising:

forming a sheet of synthetic plastic material into a convoluted roll, said material having an inherent memory;

expanding said roll about said pile, said roll thereafter contacting into close engagement with said pile because of said inherent memory;

securing said roll to said pile;

and sealing the space between said pile and said roll from the ambient water surrounding said pile sufficiently to maintain the water in said space stagnant to prevent marine borer attack on said pile.

References Cited UNITED STATES PATENTS 966,337 8/ 1910 Lamb 52-170 X 1,435,311 11/1922 Knight 138-11O 2,724,156 11/1955 Shaw 52l68 2,928,411 3/1960 Johnson 61-54 X 2,986,150 5/1961 Torian -1 3,027,610 4/1962 Liddell 61-54 X CHARLES E. OCONNELL, Primary Examiner. JACOB L. NACKENOFF, Examiner. JACOB SHAPIRO, Assistant Examiner, 

1. A METHOD OF PROTECTIVELY ENCASING A PARTIALLY SUBMERGED PILE IN SITU, COMPRISING: FORMING A SHEET OF SYNTHETIC PLASTIC MATERIAL INTO A CONVOLUTED ROLL HAVING A DIAMETER LESS THAN THE DIAMETER OF SAID PILING, SAID MATERIAL HAVING AN INHERENT MEMORY; EXPANDING SAID ROLL ABOUT SAID PILE, SAID ROLL THEREAFTER CONTRACTING INTO CLOSE ENGAGEMENT WITH SAID PILE BECAUSE OF SAID INHERENT MEMORY; SECURING SAID ROLL TO SAID PILE; AND SEALING THE SPACE BETWEEN SAID PILE AND SAID ROLL FROM THE AMBIENT WATER SURROUNDING SAID PILE SUFFICIENTLY TO MAINTAIN THE WATER IN SAID SPACE STAGNANT TO PREVENT MARINE BORER ATTACK ON SAID PILE. 